Four dead in WA road carnage

Four people have died and another was seriously injured during a horror morning on WA roads.

Crashes in Chidlow and Greenwood claimed the lives of two motorcycle riders while two people were killed and a third person was seriously injured in an early morning crash on Kwinana Freeway.

The carnage began when a truck, a van and a utility collided on the freeway near Thomas Road at 4.40am.

A motorcyclist has died after Mitchell Fwy crash. Picture: Seven News

One person died at the scene while another died later in hospital.

A third person remains in hospital in a stable condition.

The scene of a horror crash on Kwinana Freeway. Picture:Jordan Cutts/Seven News

It is believed smoke form a smouldering bushfire had significantly reduced visibility on the freeway at the time of the crash.

The freeway is closed to traffic in both directions between Anketell and Thomas roads.

Wreckage, including an upturned truck and trailer, is spread across southbound lanes of the freeway.

Police major crash investigators are at the scene.

At about 9am, a 23-year-old male motorcyclist from Wooroloo was killed when his Yamaha and a Toyota Hilux collided near the intersection of Elliot and Mathieson roads in Chidlow, 50km east of Perth.

Rider killed in Chidlow collision with a car. Picture: Seven News

A second motorcyclist died after his Harley Davidson and a car collided on Mitchell Freeway, near Warwick Road in Greenwood, also at about 9am.

The 31-year-old Padbury man was treated at the scene by St John paramedics and taken by ambulance to Royal Perth Hospital where he died from his injuries.

Southbound lanes on the freeway were closed, bringing Perth-bound traffic to a standstill.

Motorists reported taking more than two hours to get from the northern suburbs to the city.

Debris strewn across Kwinana Fwy. Picture: Seven News